There is known an apparatus for ultrasonic quality control of articles, comprising ultrasonic transducers mounted by means of a suspension assembly on a carriage with supporting rollers engaging the surface of the article being inspected (SU, A, 555333).
This device would not ensure stable positioning of the ultrasonic transducers with respect to the surface of the article under inspection, as it is devoid of operative links supporting reliable orientation of the ultrasonic transducers, as they are moved over the surface of the article. The rigid mounting of the suspension assembly with the ultrasonic transducers on the carriage would not enable them to navigate such obstacles as the beads of welds, metal splashes left by the welding operation, and the like--as in such cases a toppling torque may be produced, resulting in a breakdown of the suspension assembly of the device.
Moreover, the operation of this device is characterized by inadequate reliability and credibility of quality control of articles with either planar or curvilinear surfaces in different spatial attitudes of the device.
There is further known a scanning device for ultrasonic quality control of articles, comprising ultrasonic transducers set on the article being inspected and urged against its surface by a hold-down assembly, the transducers being mounted on a motion mechanism by means of a suspension assembly (SU, A, 1128161).
In this scanning device the suspension assembly of the ultrasonic transducers on the motion mechanism includes carriages articulated on pantographs fast with the motion mechanism.
The articulated parallelogram of each pantograph is biased by a spring and serves as the suspension assembly of the respective ultrasonic transducers.
However, this design of the suspension assembly is structurally complicated and results in relatively great dimensions and weight, which hinders the operation of quality control of articles with planar and curvilinear surfaces in different spatial attitudes of the scanning device, impairing the reliability and credibility of quality control of articles made of diverse materials, either ferromagnetic or non-ferromagnetic.
Furthermore, this design of the device would not provide for overcoming such obstacles as metal splashes left after the welding or the beads of welds, because the moment a carriage with the ultrasonic transducers rolls onto an obstacle, there is produced a toppling torque owing to the axes of the pivots joining the carriages to the pantographs being situated relatively high above the surface of the article under inspection.